Original User: szakalszaleniec
Ok, I have figured out why ArcGIS API for Flex has got sometimes problems with swfs as PictureMarkerSymbol. Everything depends on dimensions of swfs. When its canvas in Flash/Illustrator is exactly a bounding box of graphics in that swf, there is no problem at all with giving swf as PictureMarkerSymbol. The problem starts when we have got content of let's say 16px by 16px and canvas is of about 200px by 200px. After supplying swf as PictureMarkerSymbol, API centers it automatically - so even if you had your origin point in top left corner of swf, you do not have to offset in xy that icon - it is done automatically. This is the main reason why during zooming in/out of swf with wrong canvas dimensions, one can see that symbol is changing position 🙂 The center of swf is always in the correct place of MapPoint but due to centering, it still has to draw empty pixels in swf 🙂 I hope it will help others 🙂
Long story short - swf size must be exactly the same as the bounding box area of content 🙂